Electric resistance-furnace



1. srmom'mvn P. F. SARRON.

ELECTRIC RESISTANCE FURNACE.

APPLICATION FILED NOV. :3. 1918.

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Patented Mar. 23, 1920' J. SIMON AND P. F. SARRON.

ELECTRIC RESISTANCE FURNACE. APPLICATION man NOV. as, 1918.

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UNITED STATES PATENT OFFICE.

Jonas amen aim PAUL rnanco s saaaomor LYON, amen.

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To all whom it ma hat we, Jonas SIMON, of

Be it known t Lyon, France,.'and PAUL FnANgois SARRON, o Lyon, France,citizens of the French Republic, have invented acertain new and usefulImprovement in Electric Resistance- Furnaces, of which the following isa specification. v

The invention relates to apparatus for producing in general changes ofphysical condition or endothermic chemical reactions used in industry,such bein eifected by means of. a continuous eircu ation of hot asesforming a 0 Ie, the gases being eated by means 0 an electric furnace.Examples ofthe a plication of .the invention to an electric ast furnace,to a fur nace for calcining carbonates, and to a gas enerator employingthe carbonic acid of t e carbonates, will be hereinafter described.

In the rocess of operating the improved furnace t e provision of thenecessary calories is effected by means of a suitable gas or gaseousmixture, which we call .the cyclic as, which gas is previous] brought tothe eslred temperature, and w ich, after having fiiya nsmitted its heatto the materials to be treated, is again heated, and employed for afresh addition o'rf calories to the materials, this cycle of operations'being indefinitely repeated. In the case where the 1 treatment of thematerials causes the disengageinent of a gas, the latter mixes with thecyclic s, and the volume of gasi'tlius obtained 1S collected at itsissue from the furtrace, the amount of gas which is to be again used-inthe cycle is abstracted and the remaining gas is available for any use.

In the accompanying drawing Figures 1 and 2 represent a portion ofablast furnace, {which is of similar construction to a. blast urnaceheated ,with coke or charcoal, and'a roup, of elect ic gas heatersassociated t erewith. q

Fig. 1 is a vertical section through line '1--1 of Fig. 2, and shows thecrucible, the twyersiind a resistance furnace for heating the cyclicgas, a Fig. 2 is a horizontal section on line 22 ofFignL i Figs. 3 and 4show a furnace for calc ning carbonates. I

Fig. 3 is a sectional elevation on the line of Fig.4, and

Specification of Letters lateiit.

Application filed November 18, 1918. Serial No. 283,858.

Patented Mar. 23, 1 920.

F Figs. 4 is 1 section on the line 44 of n the apparatus shown in Figs.1 and 2 the twyers 5 are of a special type, because they are to irgec'ta at'a tem statute of about 1,800" whifd in the or inary blast furnaces,the air injected is only at a tein perature of 700 or 800 C. The metaltgart 6 is similar to that of the ordinary greater diameter, allowingthe introduction of a highly refractory protecting lining 7 made of amaterial such ascarborundum or cast quartz. The metal part being cooled.is itself in the usual manner, this lining somewhat cooled, which.insures its lasting a long time. These twyers are each provided with aflange 8, keyed on the flange '9 of the tube' 10 of the. resistancefurnace This furnace is formed of an outer est furnace twyers, but theyhave an orifice of F is itself lined with a.

by casting at the time of its manufacture and connecting the upperchamber 18,an

the lower chamber 19 through the arch 155 the latter chamber isconnected, by means of the pipe 20, to the conduit 21', the pipe 22 ofwhich is provided with a suitable sliding valve 23. The wholeinstallation also comprises, as in the ordinary "blast fur naces, ablower, gas-inlets at the furnace top, apparatuses for suitablerecuperators.

The working of this electrical furnaceis similar to that of theo'rdinaryblast fur naces the loading of the materials is efi'ected in the samemanner, but the amount of carbon introduced into the same is only 5 thatrequired for the reduction of the oxi and of a part of the carbonicacid, since the heat re ui'red for the various reactions and for theusion of the dross is sup lied by the cyclic gas. The latter, coming mmthe repurifying the gases and cuperators through the conduit passesucts, etc.)

After havingjn its rising course transferred its calories to thematerials to be treated,

while causing the usual reactionsand alter ations of physical condition,itreaches the furnace-top mixed with the gas arisin from,

the reactions: the gaseous mass thus ormed then passes throughthepuri'fying appa' ratuses and the amoun of the eye ic gas constitutmis then suc ed out bythe ventilator and riven back into the recu raters,whichih'ave been previously hea' by the combustion of thegas arisin fromprevious reactions the burnt gases ing collected while still hot inorder to serve for dossicatin the materials which are to compose the carge. The uantity of calories dis; charged y t the reactions can be moreor Jess mcreas by enrichin this'gas by means of gas or fuels of highcalorific capacit (gases from coking ovens heavy oils, p'etro iferousprodln this case the refractory masonry of the recuperatorsis.constructed for the temperatures required to be reached. By this methodthe cyclic gas can be brou ht to a very high temperature, which a ows ofexpendi'n less electric energy in the superheaters. n all cases, in viewof producing'a raplid ,superheating of the cgaclic gas, the super to amperature distinctly higher than t at which the gas is to have when itpasses into the crucible.

The principal advantages obtained by this electric furnace are asfollows (a) Consumption of carbon reduced to that necesa'ry or thereduction of the ore and a portion of the carbonic acid.

(b) Consum tion of electric energ less than that of the known electricbl furnaces, owing to the utilization of the gas from the reactions (c)Possibility of treating large quantities of ore as in ordina blastfurnaces.

(d) Practically comp ete absence. of ni-' i the interior of almost allknown electric blast furnaces, and consequently I of the defacts whichthey produce, such as zones of.

excessive temperature, contact with the materials to be treated,enormous consumption etc. l I v Co; plate independence of the blast funace properfrom the electric apparatus,

allowing an ordinary blast furnace to be" easily transformed into anelectric blast furnace by the simple addition of superheaters andspecial twyers.

(9) Constitution of the fusion bed as in 'tlic current to pass tfiro becom ustion of-the gas from eaters are broii ht ordinary blast furnaces,that isto say, with out previous mechanical treatment of the materials,the latter not rectuiring the elecu them.

(it) Easy regulation 0 the working of thefurnace by actin on theintensity 0 the current in the super eaters or on the speed of the cclic'g (i) ossibi 'ity of correcting, according to requirementmthecomposition of the cyclic gas, by insulating with the latter carbonatedpower 0 the gas;

in the-apparatus shown in'Figs. 3 and 4,

roducts ca able of increasing the reduc- P 5 v g for calciningcarbonates the material to be treated is fed'nto the i urnace a by meansof the known cup and con device which provides air-tightness of t efurnace at its upper part. g a

his air-tightness is secured in the lower part by means of the door 0arranged below the rati d. The cyclic gas, sucked in by t "cent on pump0, passes into the conduit f, then into the partitioned recuperator g,arranged so as to absorb the greater part ofthe calories which thecalcined materials ossess: the gas is heatedjin passi through t, andpasses through the pipes]: evel with which are tubes "0 smelte quartz s"cmbedded in a mass of pulverulent substance 7',

crease by the carbonic acid proceeding from the deco tion of thiscarbonate;

8 where the dust theredis do sited. like lieight of thefu m aee; from thtion of the calories supplied by the cyclic the top 1s thatwhich'allowsthe best utilize ,the smelted quartz tubes n, where itsheating Ill) and iscollected "the furnace-top g, by the suctiorr pipe17, which 'conveysit to the filter s. The whole seous mass is suclredrom the filter a s which 18 t0 the excess of avai the pipe t providedwith a regulating va a and passes to a gas receiver not illustratedwhichis keptconstantlyin suction. There it is collected for the tang: d.s a

V e calcined materials descend gradually at each draw and surround theregenerator g, to which they yield the greater part of y y the suctionappara .tus e: .the amo'unt of o return in the cycle'lpasses mto theconduit f. able gas pass} throulgh industrial use con-- J the caloriesthat they possess, so that, when they arrive in the hopper carryin thegrat-' ng d, they are nearly cooled. 'he drawengs are made as frequent-las sible, takmg care to stop the arriva of t e cyclic gas during theseoperations, in order to prevent reentrance of air, which would introduce nitrogen into the gaseous current. If it is desired to dispensewith regenerating the calories possessed by the calcined product, theregenerator can be omitted, and the height of the lower part of thefurnace diminished.

The principal advantages this rocess are as follows:- W

(a As the furnace does not contain solid fuel, there are no cinder-s,whereby a very pure product may be obtained, and'caking 1s avoided.

(b) Recuperation of carbonic acid capable of being employed for anyindustrial use, after having, or not/having, been freed from the vaporwhich it may contain.

(a) Great care in regulating the tempera ture of the furnace enablingtion to be obtained. n

(d) The gaseous movement, due to the suction produced in the furnace,facilitates the disengagement of the carbonic .acid from the carbonates,the tension of dissociation being much less than that which wouldproduce the re-combination of the carbonic acid with the lime.

The process is also applicable to a type of gas generator constructedand working in the same manner as the calcining furnace above described.However, the charges, instead of being only composed of the carbonate tobe treated, comprise successive layers of carbonates and of carbonatedproducts (any combustible bodies, even of bad quality, etc.) The gasarising from the reaetions started by the calorific addition of thecyclic gas, is then a mixture of carbonic acid, carbon monoxid, and alsoof hydro carbons, if'the carbonated product emp oyed contains the same.As 1n the preceding cases, the quantity of gas necessary for the cycleis previously abstracted from the gas eous mass obtained and brought inelectric heating apparatuses similar to those previpresented by aregular acouslydescribed,'to the most suitable temperature for obtainingthe best ratio The advantages presented by this gas generator are asfollows:

(o) Utilization of a portion ofthe carbon of the carbonic ,acid of thecarbonates.

(b) Utilization of a large number of carbonated products hithertodifficult or even impossible to utilize industrially {bad fuel, waste,etc.) I

(0) Production of a combustible gas free firom nitrogen.

What we claim as our invention and desire to secure-by Letters Patent ofthe United States is 1. In a. paratus for the purpose set forth thecombination of a furnace chamber, a gas heating chamber having'a inlet,a twyer connecting saidgas heating chamber to said furnace chamber,tubes of cast quartz in said gas heatin chamber in the path of r the gasbetween said inlet and said twyer, a

pulverulent electric resistance incasing said tubes and composed ofcarborundum and graphite, and electrodes for passing; electric currentthrough said resistance.

2. In apparatus for the purpose set forth the combination of an.air-tight furnace chamber, a heat recuperator at the base of saidchamber, means for admitting gas to said 'recup'erator, a gas heatingchamber, means for conducting gas from said re' cuperator to saidheating chamber, tubes of cast quartz in said gas heating chamber, inthe path of the gas, a pulverulent electric resistance incasing saidtubes and composed of carborundum and graphite, electrodes for passingelectric current through said resistance, a gas filter, and gas conduitsconnecting said filter to said recuperator and to the upper part of saidfurnace chamber respectively.

In witness whereof we have signed this specification in the presence oitwo witnesses.

JULES SIMON. PAUL FRANQOIS SARRON.

Witnesses:

JEAN GERMAIN, -MARIN VAGHON.

